Where you live different climates require different insulation r values.
Attic insulation r value code.
You can achieve better thermal performance in your attic by adding an additional layer of insulation.
2015 code requires walls to be insulated with a minimum of r 20 or r 13 5 13 5 means r 13 cavity insulation plus r 5 insulated sheathing.
You will need a higher r value of insulation if you live in the northeast than if you live in southern california.
Dte energy and consumers energy suggest an r 49 or above to be energy efficient.
R value is a measure of insulation s ability to resist heat traveling through it.
The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process.
Insulation level are specified by r value.
These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.
Where using a simulated energy performance analysis sections of ducts that are installed in accordance with section 1103 3 6 located directly on or within 5 5 inches 140 mm of the ceiling surrounded with blown in attic insulation having an r value of r 30 or greater and located such that the top of the duct is not less than 3 5 inches 89.
The higher the r value the better the thermal performance of the insulation.
If structural sheathing covers 40 or less of the exterior continuous insulation r value shall be permitted to be reduced by no more than r 3 in the locations where structural sheathing is used.
The insulation levels of an attic or of any part of a house are understood through the r value that is the value with which the insulating material is resistant to heat flow.
The higher the r value the better the thermal performance of the insulation.
The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.
Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.
There are many ways to retrofit a home with fiberglass and.
However if an r 38 was enough customers wouldn t ask why they re still too cold or hot in their home.
In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60.
Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.
The table below shows what levels of insulation are cost effective for different climates and.
For an attic the you could have an r 38 to meet the insulation code guidelines.
Energy star states that an r 60 is equal to the best performing attic insulation.
Achieving greater r values in exterior walls.
